US 20050002741 A1
A piling and method of making same for elevating or supporting a structure such as a dock in marine environments. An inner core structural support material is surrounded by an outer impact absorbing water impervious plastic shell with an impact absorbent fill between shell and inner core. The shell is sealed to the core.
1. A piling for elevation or support of a structure comprising:
a) an inner core comprising structural support material elongated along a longitudinal axis and having a bottom end and a top end;
b) an outer impact resistant, non-abrasive plastic shell surrounding but spaced from a portion of the inner core;
c) an impact absorbing intermediate material generally filling space between inner core and outer shell; and
d) a sealing member to deter entry of fluid or particles into the space between inner core and oute shell.
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49. A method of making a piling comprising:
a) selecting a length of core of structural material;
b) placing impact resistant, non-abrasive a plastic outer shell surrounding and spaced from a selected part of the core;
c) filling at least a portion of space between core and shell with impact absorbent material; and
d) sealing the space.
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a) surrounding a substantial portion of a piling with an impact resistant non-abrasive plastic shell and impact absorbing fill therebetween;
b) sealing the ends of the shell relative to the piling.
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A. Field of the Invention
The present invention relates to apparatus and methods for supporting or elevating a structure, and in particular, a support such as a piling or dock support for elevating a dock or other structure in a marine environment.
B. Problems in the Art
Pilings or elongated supports are needed to support structures that extend into the water. The supports must extend into the floor of the body of water until they hit bed rock or other sufficient underlying support material. Alternatively or in addition, footings can be constructed to assist in providing a foundation for the support. The top of the piling or support usually extends above water level.
These types of pilings or supports are widely used, especially in lakes and coastal areas where commercial and recreational water activity is most prominent.
Many factors are relevant to selection of these pilings. Durability is almost universally desirable. However, especially for individuals, cost is very important. For example, the owner of a small waterfront vacation property cannot afford expensive commercial-grade pilings to support a dock.
Maneuverability is also important, especially for those lacking industrial equipment, such as “do-it-yourselfers”.
Environmental issues are also important, and increasingly so.
Traditionally, natural wood has been used as pilings. However, as is widely known, even wood that is naturally resistant to the effects of water degrades over time. They also tend to be heavy because they are usually solid. Their relatively low cost, along with the ability to manufacture them a variety of lengths without substantial cost, has made them a conventional choice over the years.
Although the effective life of such pilings can still be years, the fact that they are susceptible to degradation by the elements and wood attacking organisms can greatly reduce their effective life. The expense and resources required to replace them is substantial.
Many attempts have been made to improve upon untreated wood pilings for marine use. Treated wood (chemicals and/or pressure) can slow down decay. However, wood remains susceptible, over time, to degradation. Additionally such chemicals and treatments can involve environmentally adverse substances. Therefore, the increase in effective life by such treatments may not be a good trade off.
Non-wood materials such as concrete, metal, and even solid plastic have been attempted. Reinforced concrete is capable of excellent support in compression. However, like wood, over a large span of time it is susceptible to degradation. The cement can erode, chip, or crack. The reinforcing re-bar can rust and structural integrity of the concrete piling can fail. This is especially true in marine conditions where the water freezes and thaws. Additionally, concrete is very heavy and thus difficult to maneuver. It also is unforgiving in terms of impact and damage when boats come into abutment with it.
Tubular steel and aluminum pilings are lighter and more maneuverable. However, over long periods of time, especially in salt water environments, metals can degrade. Such degradation and deterioration can release substances into the water that are not environmentally friendly and can cause pollution. Metals are also unforgiving relative to impact.
Solid plastic pilings have been proposed. They tend to have less structural robustness and higher weight because they are solid.
Several attempts have been made to create a shell to place around the structural support to try to protect it. These tend to be temporary fixes as it is difficult to get good, waterproof, long-lasting fit and attachment.
Despite all of the activity in developing different types of pilings of this nature, there remains room for improvement in the art.
It is therefore a primary object, feature, aspect or advantage of the present invention to provide a dock support or piling which improves or solves problems and deficiencies in the art.
Additional objects, features, aspects, and advantages of the present invention include a dock piling or support which:
A still further object, feature, aspect or advantage of the present invention relates to a method of supporting a dock or other structure.
A still further object, feature, aspect or advantage of the present invention involves a method of manufacturing a dock support or piling.
These and other objects, features, and advantages of the present invention will become more apparent with reference to the accompanying specification and claims.
An apparatus according to the invention includes an inner core made of structural support material. An outer plastic shell is adapted to surround a portion of the inner core with space inbetween. An impact absorbent intermediate material fills the space between inner core and outer shell. A sealing member deters entry of water or substances into the space between inner core and outer shell.
In another aspect of the invention, a method of making a piling or support comprises selecting a length of core or structural material, placing a plastic outer shell surrounding and spaced from a selected portion of the core filling at least a portion of the space with impact absorbing material, and sealing the space from the environment.
One aspect of the invention involves utilizing pelletized material as the impact absorbent material. It is placed between the core and shell and packed or tamped in a manner to spread it uniformly across the cross-section of the composite structure.
In another aspect, the composite structure can be assembled by placing a first layer of impact absorbent substance near the bottom of the core and shell and compacting it, then placing as many succeeding layers as are needed to reach the top of the space between core and shell. Optionally, blocks or gaskets can be placed between layers.
The invention can take many forms and embodiments. In order to provide a better understanding of the invention, several exemplary embodiments will now be described in detail.
Frequent reference will be taken to the accompanying drawings. Reference numbers will be used to indicate certain parts and locations in the drawings. The same reference numbers will be used to indicate the same parts and locations throughout the drawings, unless otherwise indicated.
The exemplary embodiments will be described in the context of dock supports or pilings used to support the structure needed to support a marine dock. In particular, the exemplary embodiments will be described in association with docks for residential waterfront properties for sunbathing, fishing, and boarding and unboarding recreational watercraft. Such docks usually extend anywhere from 10 feet to 100 feet from the shoreline. Normally, the water level to floor of the body of water rarely exceeds 20 or 30 feet deep. Of course, different dock lengths and water depths are possible.
In particular, this description will assume docks are placed in salt water along a coastal area.
As can be seen in
As indicated at
The length of pilings 2 is usually anywhere from 8 feet to 40 feet depending on depth of the water and the distance pilings 2 that must be inserted below sea bed level. Average insertion depth below sea bed 40 is around 4 feet. Spacing between pilings 2 is usually between 4 feet and 6 feet for these types of docks.
An outer shell 20 has an open bottom end 22, open top end 24, and a hollow intermediate section 26. It has a 10 to 24 inch O.D. and a ¼ inch and greater wall thickness. One material it could be made from is high-density polyethylene (HDPE) in a round-in-cross-section tube of a length that is on the same order of the length as inner core 10. It is adapted to concentrically surround a substantial portion of the length of inner core 10 such that there is a space (e.g. approximately 2 inches) between the outside of inner core 10 and the inside of shell 20.
A steel ring 28 having a center aperture of slightly larger than 8 inches diameter is welded (see welds 29 in
Ring 28 would therefore form a rigid lower stop for shell 20. The outside diameter of ring 28 would be approximately 8-24 inches such that shell 20 could be slid concentrically over inner core 10 and down into abutment with ring 28. Before seating shell 20 on top of ring 28, a rubber washer seal 32 could be slid down inner core 10 into abutment on the top of ring 28. Seal 32 could be elastomeric and have an inner aperture less than 8 inches diameter and a cross-sectional diameter of more than the space between inner core 10 and shell 20 when positioned as in
A fill material 30 is placed in the space between core 10 and shell 20. In this exemplary embodiment, fill 30 is a pelletized rubber with the average diameter of the pellets being less than the cross-sectional thickness of space between core 10 and shell 20. As illustrated in
A top seal 34 (here in the nature of an elastomeric O-ring) could optionally be positioned as shown in
A piling cap 38 could be fit over the top of piling 2. As indicated at reference numerals 39, a seal (e.g. silicone or other caulking) could seal cap 38 to shell 30 and prevent water from entering into the tops 14 or 24 of inner core 10 or outer shell 20. As shown in
An example of a manufacturing/assembly process for this embodiment is set forth at SDS Manufacturing procedure #102, later in this description.
Piling 2A of
But further, composite piling 2 is economical to manufacture and therefore can be sold at a relatively low price. By reference to
As previously discussed, the length of inner core 10 would be selected. Obviously, a standardized or set of standardized lengths of cores 10 could be selected and an inventory built up for those standardized lengths for manufacturing or purchasing economies. Corresponding shells 20 of lengths less than those of core 10 can be manufactured by conventional molding or extrusion processes (or cutting from stock) to create the tubular shells 10 of the desired materials. One advantage of using HDPE is it could be made of recycled plastic, making it more economical and better for the general environment. Plastic can be engineered to have desired properties (impact resistance, impact absorbability, UV resistance, fluid impermeability, etc.). The inside diameters of the shell can also be engineered to choice leaving a space of desired volume when concentrically positioned over core 10.
A ring 28 can be welded or otherwise fixed at a desired position near the end 12 of core 10. The lower rubber washer seal 32 could be positioned as shown in
Piling 2A can be up to tens of feet long (e.g. 40 feet). Shell 20 would be positioned concentrically over core 10 and recycled rubber pellet fill 30 is poured into the space until it fills up approximately one foot above recycled rubber washer seal 32. Although not required, all the rubber components of the apparatus could be recycled rubber. Using a long tool, the pelletized rubber could be tamped down to compress it so the pellets are packed together as much as possible. A first recycled rubber gasket 36A can then be moved down the outside of core 10 over the first foot of pelletized fill 30 to retain that fill and to create a spacer to hold shell 20 concentrically from core 10. A next one to three feet of fill 30 could be poured in, tamped and covered with a succeeding gasket 36B (see
As indicated at
Even when assembled (shown diagrammatically at
When installed, shell 20 shields inner core 10 from water or organisms that could try to attach or degrade core 10 by nature of the properties of the plastic. The composite structure presents a buffer between core 10 and watercraft.
Additionally, the relatively economical composite structure presents the ability for aesthetic or functional additions. Examples include color, indicia (e.g., designs, instructions or words or letters), and texturing.
Utilization of O-rings or washers 32, 36, and 34 is a relatively inexpensive way of assuring concentric positioning of shell 20 on core 10. Pelletized recycled rubber 30 is an inexpensive yet highly effective, long-lasting pile.
The composite structure also has no environmentally adverse substances inside the structure that could interface with the water.
The amount of tamping or compression of pellets 30, and their size, shape, and material, can be varied. The ability to vary these factors is improved because the fill 30 will basically be isolated or insulated from the water by shell 20 and sealing members such as O-rings 32, 34 and 36, and/or cap 38.
The nature of foam 31 is that it could be economically injected into the space between core 10B and shell 20 along the length of structure 2B. Washers 32, 34, and/or 36 may or may not be needed. The shell 20 can be maintained concentric (see, e.g., manufacturing procedure SDS #101, described later), the washers may not be needed as the urethane foam, when set up, hardens to a relatively firm consistency yet retains impact absorbing ability and some resiliency.
Installation of any of the pilings 2 has been generally described above. The length of pilings 2 must be selected. The lengths can vary for pilings for each dock. Stringers 44 can be attached by bolts 46 by well-known methods which are well within the skill of those skilled in the art. Standard marine construction is bolted through. Preferably, only stainless steel bots, nuts, and washers are used. Necessary holes can be drilled relatively easily with commonly available tools.
Election of color, exterior texture, cap (or not), and other functional or decorative features can be possible with pilings 2.
Once installed with stringers 44, deck 48 can be added to stringers 44. If desired, sea wall cap 50 or other structures can also be added.
The foregoing exemplary embodiments are intended to provide illustrations of just a few forms the invention can take and are not made by way of limitation. The scope and boundaries of the invention are defined solely by the claims.
Variations obvious to those skilled in the art will be included within the invention. For example, the exact dimensions, size and shape of the components can vary.
Additionally, the materials utilized can vary. Specific examples that could be used with the aforementioned embodiments are as follows. These are by example only and not by way of limitation.
Shell 20 can be HDPE with the following composition (and percentage by weight): low density polyethylene between 20% and 25%; high density polyethylene 35% to 45%; polypropylene 35% to 45%; additives—carbon black 2%, foaming agent, emulsifies and antioxidants, as required for suitable extrusion of plastic pipe for use in a marine environment. Alternatively, shell 20 could be vinyl.
Inner core 10 can be hot formed structural carbon steel (ASTM A 501); 58,000 psi tensile strength; 36,000 psi yield, Brinell hardness 121 on the (B scale), minimum wall thickness of one eighth inch and greater to suit application and loading. As stated earlier, the material and material dimensions and characteristics can be selected according to need or desire.
Alternatively, tubular core 10 could be made of marine grade 6061 aluminum conforming to federal specification QQ-A-250/11 (formally QQ-A-327). If fiberglass, tubular core 10 could be glass reinforced polyester continuous formed tubing having a high strength to weight ratio, a good dimensional stability and resistant to weather and chemical corrosion.
Other core shapes, materials, configurations, and characteristics are possible. For example, instead of a round-in-cross-section tubular or solid core, it can be made of other cross-section shapes (e.g. triangular, rectangular or square, other polygons). It could also be made of other structural shapes, such as an I-beam, H-beam, or other structural cross-section, especially with expandable foam embodiments. It is believed that round outside perimeter of the core is best for the embodiments using a pelletized fill between core and outer shell. Furthermore, it is believed the expanding foam embodiments are better suited for cores like wood or fiberglass than steel or aluminum. Also, rubber washers or O-Rings are probably not necessary with expanded foam embodiments.
Rubber pellet fill 30 could be recycled rubber pellets that ground up recycled rubber tires with mesh size of pellets to be altered to accommodate design requirements. Pellets will provide the filler and cushion between the recycled rubber washers or O-rings and the outer shell and core.
Washers or O-rings 32, 34, 36 can be recycled or vulcanized rubber with a durometer of 70 and approximately one-inch in cross-section. Preferably, but not required, parts 32, 34, and 36 are either all O-rings, or all washers. A ring washer 28 could be stamped from sheet material.
The exemplary embodiments have been described regarding a dock support or piling. Other support functions are possible including in non-marine environments where protection of the core from environmental conditions or some impact is desirable.
Plastic shell 20 can have texturing that simulates natural elements. The texturing could also be arbitrary or include thinner and thicker areas. It could also include molded end or extruded indicia such as numbers or letters. Plastic of shell 20 could also be colored to different colors.
For the embodiments utilizing an expandable foam filler, one option that could be used for both wood and fiberglass core pilings include Suremix 6000 or equal expandable foam urethane available from commercial sources. It has a working time of 10 minutes, handling strength in 10 minutes, and full cure time of one hour. When cured it has a tensile strength of 2,000 and an elongation of 10%. Another example would be rigid urethane foams of two component expanding system. These tend to be very strong and durable and can add structural strength and resist tearing and compression set. These types of foams are commercially available and can be formulated to add structural strength as an encapsulation material. They have double the working time and fully cure in about two hours compared to the previously described optional expandable foam. When cured, it has a strength similar to the first option expandable foam.
It can therefore be seen that different pilings 2 described above promote longer effective life of the pilings than traditional wooden, concrete, steel based pilings, are environmentally friendly, and are forgiving and impact absorbing for all watercraft and other water carrying objects. The plastic also resists attachment of marine organisms and animals as well as resists attachment of ice, which can cause damage by heaving.
Pilings 2 tend to be lighter weight, safer and easier to handle, install, maintain, and modify than traditional pilings, and in some embodiments use recycled plastic and rubber. The inner core can be selected for adequate structural integrity and robustness whereas the outer shell can be selected for aesthetic or decorative features.
Pilings 2 can be manufactured to length. Mounting holes for stringers or the like could be pre-manufactured or made during installation. The mounting bolts could have sealing gaskets or otherwise be sealed, but this may not be necessary because they are above normal water line. Caulking or sealing gaskets could be used on opposite sides of the bolt to prevent water from entering. The composite structures can be drilled or cut with conventional tools.
The outer plastic shell could include sizes bigger than 10 inches. Sizes up to 18 inches or more are included.
A typical small dock 8 feet wide by 25 feet long requires on the order of 12 pilings. Pilings 2 as above described are economical and therefore can multiply savings in cost not only for the original pilings, but increased durability would delay maintenance and replacement over the years.
Shell 20 could have other cross-sectional shapes such as square, 10 inch plastic tubing with one quarter inch wall thickness. Core 10 could also have different cross-sectional shapes.
When using expandable urethane foam, as is known in the art, when inserting the foam space for expansion must be left. The urethane will provide air and watertight seal and bond core 10 to shell 20 together as one-piece. The ends can be capped and sealed if desired. The composite piling 2 with expandable foam is indicated for pilings up to 24 inches in diameter.
Different manufacturing/assembly procedures for different embodiments can be used. Some examples, for illustration, are set forth below.
SDS Manufacturing Procedure #102.
3.0 Inspection procedure
Check straightness over its length, and other defects that would affect structural integrity.
SDS Manufacturing Procedure #101.
3.0 Inspection Procedure
Check straightness over its length, (should not be bowed more than ¼ inch over its length). Inspect for any defects that would affect structural integrity.
4.0 Assembly Procedure
4.3 The assembly should be visually inspected for appearance, and stored for shipment.
5.0 Optional Driving Tip.
5.1 The Steel and Aluminum core pilings will be offered with a pointed tip (e.g. see ref. no. 3 at